Something is definitely wrong with this spell and possibly others in the same spell line.
While in Paw the spell was almost completely useless due to the tight corners in certain areas. This was not the way the spell line worked on live.
You should be able to assist the puller and cast the spell.
(I know this was posted already
http://www.project1999.org/forums/sh...ght=line+sight but it's marked as resolved and clearly is not resolved.)